A behind-the-scenes U.S. intelligence community fight over the merits of publicly scorning President Trump has burst into the open recently, with the CIA’s former Moscow station chief accusing Obama-era spymaster John O. Brennan of crossing a red line through incessant Twitter and cable news excoriations of the current commander in chief.

In addition to claiming that Mr. Brennan is aiding a Kremlin plot to deepen America’s partisan divide, former CIA Clandestine Service Officer Daniel Hoffman says the former CIA director has actually jeopardized national security by publicly insinuating that Russian President Vladimir Putin may be blackmailing Mr. Trump.

Mr. Brennan made the insinuation in late-March when he asserted during an appearance on MSNBC’s “Morning Joe” that Mr. Trump is “afraid of the president of Russia” and that “one can speculate as to why.”

“The Russians may have something on [Mr. Trump] personally, that they could always roll out and make his life more difficult,” Mr. Brennan said. “That [Mr. Trump] has had this fawning attitude toward Mr. Putin…say[s] to me that he does have something to fear and something very serious to fear.”

The comments quickly became fodder for headlines in other news outlets. But they also had something of an explosive impact inside the intelligence community, where many recoiled at the notion that the former CIA chief had made a public declaration on a matter U.S. spy agencies have never weighed in on conclusively.

Apparently aware of this, Mr. Brennan wasted little time trying to rectify the situation by reiterating that he was only speculating. Within just a few hours of the MSNBC interview, he told The New York Times that, “I do not know if the Russians have something on Donald Trump that they could use as blackmail.”

“What I found cringe-worthy,” he says, “is that Brennan was insinuating that Vladimir Putin could control President Trump and that Brennan’s choice of the word ‘speculate’ would be lost on the audience because of his previous position as director of the CIA.”

The former station chief initially took his concern public with an early-April article for The Cipher Brief, a publication known for its commentary by former intelligence officials. There, Mr. Hoffman argued that vital foreign liaison partners, upon whom American spy agencies depend to steal secrets from Russia and other adversaries, “must have been shocked and concerned over Brennan’s allegation.”

“I felt like if Brennan wanted to make the kind of allegation he made, he should have done it through the established process, by going and speaking privately about it to Special Counsel Robert Mueller,” Mr. Hoffman more recently told The Washington Times.

“That way, he could avoid collateral damage to those with whom we are working, whether it’s a spy who’s risking his life to be the source of secrets for us, who’s now going to wonder whether he should be doing that because his boss Vladimir Putin has dirt on our president, or a partner liaison service, which might want to work with us against the Russia target.”

It’s an argument whose nuance has so far gone largely overlooked by the mainstream media. To the contrary, several news outlets have had a field day focusing on more rudimentary insults Mr. Brennan has hurled at Mr. Trump, such as his recent assertion on Twitter that the president’s “self-adoration is disgraceful.”

The former CIA director made headlines tweeting last month that the president’s “kakistocracy” — a reference to government run by the worst, least qualified or most unscrupulous citizens — was “collapsing after its lamentable journey.”

His criticism comes against a backdrop in which U.S. lawmakers will debate this week whether to embrace longtime Clandestine Service operative Gina Haspel as the next CIA director. If confirmed, Ms. Haspel will become the first female director and the first career agency officer in decades with a background in operations — rather than a political appointee — to serve in the post.

Conservatives have largely disregarded his Trump criticism as base partisanship emanating from a former official of the Obama administration, where Mr. Brennan served in various intelligence-related advisory capacities prior to being tapped to head the CIA from 2013 through 2017.

But within the wider intelligence community, Mr. Brennan’s statements, as well as Mr. Hoffman’s attempt to counter them, are being watched with intense interest.

“This dispute that’s going on raises two issues,” said former CIA and National Security Agency Director Michael V. Hayden. “Number one is, look, the Russians are doing things to mess with our heads and to divide us and so when we get into this kind of discussion, however well merited it might be, it does seem to push the Russian agenda a bit.”

“At the same time, we’re allowed to speak out and to argue. The Russian objective may well be to get us to argue with one another and here we are in this argument. But that’s not an ironclad argument against arguing,” Mr. Hayden told The Times.

“Number two though, is that we have a president who’s more norm busting than any president in our history, so a lot of people who think norms should be respected are pushing back,” he said. “But at what point do we run the danger that in pushing back, we violate our own norms?”

In his new book, ‘The Assault on Intelligence; American National Security in an Age of Lies,’ Mr. Hayden goes to length exploring such challenges facing the intelligence community in the Trump era.

It’s an era some believe got off to a rocky start when Mr. Trump went off script during a visit to CIA headquarters in the early days of his presidency. Speaking at the time in front of the Memorial Wall honoring agency employees who’ve died in the line of duty, Mr. Trump suddenly began harping about the media’s unfair treatment of him, personally, saying journalists “are the most dishonest human beings on earth.”

One former high-level intelligence official, who spoke on condition of anonymity, said the fight now playing out between Mr. Brennan and Mr. Hoffman is representative of a sharp division within the intelligence community over whether and how it should respond to such behavior.

“Brennan comes down on the gotta speak out side and Hoffman comes out on the you’re only adding fuel to the fire side,” said the former official, who added that while both have their merits, Mr. Brennan has gone so far in his criticisms of Mr. Trump that he’s merely feeding the view held by some administration supporters that there’s a “deep state” conspiring to undermine president.

Another former high-level official, who also spoke only on condition of anonymity, said Mr. Brennan’s blackmail speculation on live television was a kind of “holy [expletive] moment” for many in the intelligence community.

Interest only elevated a few weeks later, when Mr. Hoffman entered the fray to call the former director out.

It’s gotten personal

That a visceral fight is now playing out between the two former high-level CIA officials is “unprecedented,” said yet another intelligence source, who also spoke on condition of not being named.

The source suggested the dispute may actually be a very personal between a long-time field operator and his former bureaucrat-analyst boss. Mr. Brennan spent 25 years at the CIA as an analyst before rising through the politically-appointed bureaucratic ranks to head the agency under Mr. Obama, while Mr. Hoffman’s career was one dominated more by time in the bare-knuckle and secretive shadows of the intelligence world.

“They’re not peers in any sense,” said the source, who knows both men personally. “Dan was a division chief, senior operations guy, but that’s many, many rungs away from director of the CIA…[Dan] had very senior positions, but not anywhere near John’s stature.”

For Mr. Hoffman, it’s irrelevant. He says his argument is simple: Mr. Brennan went too far with the blackmail speculation and his comments could jeopardize sensitive foreign intelligence sources relied upon by Washington.

In an interview with The Times, the former station chief lamented that other media outlets have so-far failed to grasp the gravity of what he’s getting at.

During April interviews on National Public Radio and NBC’s “Meet the Press,” hosts lobbed Mr. Brennan questions only about whether he was concerned by Mr. Hoffman’s other assertion, that Mr. Brennan is “doing Putin’s bidding” by attacking Mr. Trump in a way that could be construed as divisive and partisan.

“When Brennan was on ‘Meet the Press’ with Chuck Todd, they twisted my [argument] into something it wasn’t,” said Mr. Hoffman. “John Brennan made it appear as if I was criticizing him for criticizing Trump’s Russia policy, when in fact, I had a much more nuanced point that I was making, which was that John Brennan should not be speculating about Vladimir Putin being able to blackmail the president.”

He added that Mr. Brennan is “certainly protected by freedom of speech to criticize a current administration in a partisan way, what he did took it too far in my view.”

Nick Shapiro, who formerly Mr. Brennan’s deputy chief of staff at the CIA, took issue with Mr. Hoffman’s “logic.”

“One could even argue that it is Dan who is doing Putin’s bidding by criticizing Brennan for criticizing Trump, as Russia seems to welcome any and all discord and since Putin and Trump seem so closely aligned,” Mr. Shapiro told The Times.

“These are not normal days. We’re seeing a growing chorus of former national security leaders who have served presidents of both parties, speaking out to warn us about Trump,” he said. “They aren’t becoming partisans, this isn’t about politics. Instead of throwing accusations at these dedicated patriots, we should all be concerned about why they feel the need to speak out — not that they are doing so.”

Further, Mr. Shapiro called it absurd for Mr. Hoffman to focus on the potentially jeopardizing impact that Mr. Brennan’s “speculation” on Mr. Putin blackmailing Mr. Trump might have on foreign spying alliances. “It is quite the overreach to hang it on Brennan — after all that Trump has done and himself said — that allies would be concerned,” he said.

Mr. Hoffman disagreed. “There’s certainly plenty to debate about the president’s policy toward Russia, his holding back on sanctions and the laudatory things he’s said about Vladimir Putin,” the former station chief said.

“But there’s a difference between that and insinuating — from a position of someone who should have known as director of the CIA — that Vladimir Putin could blackmail the president.